Was just reading what Dibart said and something sprang to mind. Back in the day, Vox used to test their amps by dropping them down a flight of stairs. It was shown on a documentary on Vox amps (which I still have- the documentary not the amp!!) and it was amazing to see the amp still working fine.
Also back in the day, when I used an AC 30 the handle "connectors" were made out of Mezzack (sp?) which was brittle. This decided to give way as the roadie was carrying it down a metal staircase. The inevitable happened.
My Dad (a jig and tool maker/air mechanic/electrician) made new ones up in solid steel. I passed a few of those around the AC30 owners of Cardiff!
So where are we:-
Contact GC straight away.
If you decide to keep it after compensation, get it checked out by a good amp tech.
If you want the name of a guy who makes the best custom cabinets around let me know - he ships o/seas.